Ever since cavemen invented the wheel, people have been fascinated by machines and what they could do. From simple pulleys and screws to intricate medical robots, kids can discover all kinds of machines and learn how they work in this dynamic new book in the Explore It series. Special tour guides like Leonardo da Vinci, Sir Isaac Newton, and even Laika (the first Dog Astronaut) describe the fascinating process from discovery to invention of some of the world's most important machinery like airplanes, windmills, clocks, rockets, x-rays, and even rollercoasters. Incredible interactive 3-D pop-ups, pull-outs, flaps, diagrams, and an illustrated glossary bring the information to life and help to illustrate the principles of mechanics in a fun, age-appropriate manner.